Citing insiders familiar with the incident, local media reported the armed assault came amid concerns about a rise in carjackings in the nation's capital, adding that it was not the first time this year that an acting lawmaker has been attacked.
The Metropolitan Police Department and the Capitol Police have yet to respond to requests for comments, reports said.
However, Cuellar's office confirmed to the media that Cuellar was attacked, but that he was not injured in the accident. His office also said the city's alert system notified residents of an investigation into a carjacking of a Honda SUV with Texas license plates.
Reports have detailed that the incident took place at about 9:30 p.m. local time about a mile from the US Capitol, and that it involved three "armed assailants" who also reportedly stole the Texas lawmaker's cellphone.